The closeness and comfort of a shave is substantially dictated by the relative positions of the skin contacting elements of a razor head. In a typical razor head, the skin contacting elements include a guard member, at least one and preferably two blades, and a cap member. The relative spacing between each of these elements, the angles at which the blades are disposed, their resulting angular displacement with respect to the surface being shaved, and the exposure of the blade edges, relative to a tangent from the guard member to the cap, affect the closeness and comfort of the shave. As used herein the term "seat span" is used to indicate the distance between the edge of the seat blade, i.e. the forward blade, and the closest point on the guard member contacted by a tangent from edge of the seat blade to the guard member. The "cap span" is used to indicate the distance between the edge of the cap blade, i.e. the rear blade, and the point of contact of a tangent line extending from the cap blade edge and the guard blade, typically the edge of the guard blade. The "shave angle" is meant to indicate the angle between a plane extending through the middle and the apex of a blade (exiting the edge) and a tangent between the blade edge and either the guard member for the guard blade, or the seat blade. Lastly, the term "blade exposure" as used herein is intended to mean the perpendicular distance from the edge of a blade to a tangent drawn to both the cap and guard. Those skilled in the art will appreciate that the blade exposure is typically considered positive when the blade edge is disposed above this tangent line and is considered negative when the blade edge is positioned below this tangent line.
In recognition of the fact that surfaces being shaved are not perfectly planar but comprise a large number of contours, it is believed that a more comfortable shave may be obtained by providing a razor with skin engaging elements which are moveable such that their respective distances and angles are adjustable to the surface being shaved in response to shaving forces.
Furthermore, it would be beneficial to provide a razor head with adjustable distances and relative angles of the skin contacting elements and which is relatively simple and inexpensive to manufacture.
As used herein, the term "razor head" is meant to include both razor cartridges adapted to be utilized with a separate handle, as well as the upper, operative elements of a disposable razor to which a handle is permanently attached. For ease of explanation, the present invention is described herein as a disposable cartridge adapted for attachment to a separate handle.